Internal combustion engine having by-
pass for automatically actuating an
auxiliary scavenger piston



Oct. 11, 1966 D. A. DREISBACH INTERNAL COMBUSTION ENGINE HAVING BY-PASSFOR AUTOMATICALLY AGTUATING AN AUXILIARY SCAVENGER PISTON Original FiledJan. 24, 1963 6 She ts-Sheet 1 FIG! INVENTOR.

DALE A. DREISBACH ATTORNEY Oct. 11, 1966 Qriginal Filed Jan. 24, 1965 D.A. DREISBACH Re. 26,103

INTERNAL COMBUSTION ENGINE HAVING BY-PASS FOR AUTOMATICALLY ACTUATING ANAUXILIARY SCAVENGER PISTON 6 Sheets-Sheet 2 FIG.3

INVENTOR.

DALE A. DREISBACH BY com/Q ELM ATTORNEY /'2! 9-43 g 23 a; H 5 f f 1 415/ ,J .4 K

Oct. 11, 1966 D. A. DREISBACH INTERNAL COMBUSTION ENGINE HAVING BY-PASSFOR AUTOMATICALLY ACTUATING AN AUXILIARY SCAVENGER PISTON gjriginalFiled Jan. 24, 1963 6 Sheets-Sheet 5 FIG.5

FIG.4

INVENTOR.

DALE A. DREISBACH ATTORNEY Oct. 11, 1966 D. A. DREISBACH INTERNALCOMBUSTION ENGINE HAVING B Y-PASS FOR AUTOMATICALLY AG'IUATING ANAUXILIARY SCAVENGER PISTON flriginal Filed Jan. 24, 1963 6 Sheets-Sheet4 FIG? FIG.6

INVENTOR.

DALE A. DREISBACH ATTORNEY Oct. 11, 1966 D. A. DREISBACH 26,103

INTERNAL COMBUSTION ENGINE HAVING BY-PASS FOR AUTOMATICALLY ACTUATING ANAUXILIARY SGAVENGER PISTON Original Filed Jan. 24. 1963 6 Sheets-Sheet 5F!G.8 FIG.9

6/ /tj '53 2a ,-5I

K J 3i 1 H INVENTOR. DALE A DREISBACH 0mm ym ATTORNEY 6 Sheets-Sheet 6FIGJO INVENTOR.

DALE A. DREISBACH ATTORNEY United States Patent 26,103 INTERNALCOMBUSTION ENGINE HAVING BY- PASS FOR AUTOMATICALLY ACTUATING ANAUXILIARY SCAVENGER PISTON Dale A. Dreisbach, 6768 Hinsdale St., Hiram,Ohio Original No. 3,199,497, dated Aug. 10, 1965, Ser. No. 253,645. Jan.24, 1963. Application for reissue Sept. 24, 1965, Ser. No. 491,504

Claims. (Cl. 123-66) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

This invention relates to the art of internal combustion engines and inparticular relates to an internal combustion engine of the type whereinan auxiliary, or scavenger piston is employed for the purpose ofproviding one power stroke during each cycle of operation.

Internal combustion engines of this type are well known in the art and,in essence, comprise a primary piston that is operated by ignited gas inconventional fashion, together with a secondary or auxiliary piston thatmoves in timed coaction with the primary piston, with the auxiliarypiston performing certain of the functions that are normally performedby the single piston of a four stroke cycle engine.

From the above, it is manifest that timed coaction between thereciprocal movements of the primary and auxiliary pistons is requiredfor elfective operation and to this end, in the past, such timedcoaction has been achieved by the use of linkages, cams, chain drives,and other types of mechanical connections. The difficulties attendant tothe use of such mechanical connections are believed apparent, since thesame are subject to high wear and mechanical malfunction, with theresult that the utility of engines of this type has been somewhatlimited in the past.

It has been discovered that the aforementioned disadvantages can beobviated by providing a freely reciprocating auxiliary piston which isnot connected to the main piston in any way. Furthermore, it has beenfound that by-pass means that serve to divert a portion of the ignitedpressurized gases around the primary piston to a point above thesecondary piston can be utilized with the pressure of these divertedgases being applied to the upper face of the auxiliary piston so as topropel the same downwardly after the primary piston has completed apredetermined portion of its power stroke. This controlled downwardmovement of the auxiliary piston permits the auxiliary piston to performthe dual function of sweeping out the spent gas above the downwardlytraveling primary piston, while simultaneously drawing in a fresh chargeof fuel to be ignited upon return of the primary and secondary pistonsto igniting position.

Production of an improved internal combustion engine having the aboveadvantages accordingly becomes the principal object of this invention,with other objects thereof becoming more apparent upon a reading of thefollowing brief specification, considered and interpreted in the lightof the accompanying drawings.

Of the drawings:

FIGURE 1 is a perspective view broken away and in section and showingthe construction of the improved internal combustion engine.

FIGURES 2 through 10, inclusive, are sectional views showing theposition of the component parts of the internal combustion engine invarious phases of operation.

Referring now to the drawings and in particular to FIGURE 1. theimproved internal combustion engine, generally designated by the numeral10, is shown including a cylindrical body portion that defines a mainReissued Oct. 11, 1966 ice combustion chamber 21 of cylindricalconfiguration, as well as an auxiliary cylindrical chamber 22 that isshown concentrically disposed with respect to the chamber 21, with thechamber 22 slidably receiving the piston rod 51 of the auxiliary piston,as shown in FIGURE 1 and as will be described in greater detail at alater point.

The main combustion chamber 21 includes an exhaust port 23 and bypassport 24 which is preferably located just below the horizontal plane ofthe exhaust port 23, as is clearly shown in FIGURES 2 through 10 of thedrawings. The chamber 21 also has an adjacent zone 29 that serves thedual function of (1) acting as a by-pass chamber and (2) acting as anignition chamber, as will be subsequently described in greater detail. Asecond by-pass port 25 opens into the upper end of the auxiliary chamber22, as shown in FIGURES 2 through 8 and these by-pass ports 24 and 25are connected by a by-pass conduit 26.

A spark plug 28 is disposed on the cylindrical body portion 20 andextends into the zone 29 that is provided at the upper end of the maincombustion chamber 21, while inlet port 30 opens into the upper end ofthe main combustion chamber 21 as shown in FIGURES 1 through 8.

In this regard, the inlet port 30 may be of any conventionalconstruction, such as a reed valve, with the drawings illustrating aport 30 that is normally scaled against the entrance of fluid by the useof a valve stem 31 whose head 32 is normally urged into the seatedposition of FIGURES 2 through 6 by a spring 33 which seats againstwasher 34 and lower head portion 31a of valve stem 31, with the usualsupply line 35 supplying the inlet port 30 with fluid as required.

The primary piston is of an appropriate diameter to be reciprocal withinthe chamber 21, with the peripheral edge thereof being received againstthe circular walls of the combustion chamber 21. In this regard, it isunderstood that the piston 40 is only slightly spaced from the walls ofthe cylinder in conformity with normal requirements for free movementwith the spacing shown in the drawings being exaggerated for purposes ofillustration. The piston 40 also has the usual connecting rod 41attached to it and journaled about an eccentric arm 42 so as to causethe piston 40 to reciprocate between the upper limit shown in FIGURE 2and the lower limit shown in FIGURE 7 of the drawings.

The piston 40 further has a top surface 43 as well as a peripheral edgesurface 44 and a bore or opening 45 which extends downwardly andoutwardly from the top surface 43 at an angle so as to open into theperipheral edge 44 as shown in the drawings, with the opening in edge 44being designated by the numeral 46.

The usual packing rings 47, 47 are disposed in the periphery of thepiston to prevent the escape of gas between the peripheral edge of thepiston and the wall of the combustion chamber 21. These rings aredesigned in conventional fashion to obtain the desired sliding contactwith the walls of the chamber in known manner.

The auxiliary piston has been designed for free reciprocation in theauxiliary chamber 22 and accordingly includes a piston head 50 and apiston rod 51. It is to be understood that the auxiliary piston rod 51is spaced slightly from the walls of the chamber 22 to permit freereciprocal movement of the rod within the chamber, with this spacingalso being exaggerated in the drawings for clarity of illustration.

The piston head 50 further has a lower surface 52, while the piston rod51 has an upper surface 53 that defines the upper face of the auxiliarypiston for the purpose of this invention. Protuberances 54, 54 projectfrom the surface 52 for the purpose of providing spacing be- 3 tween theprimary and auxiliary pistons as shown in FIGURES 2 and 8 through 10 ofthe drawings.

In addition to the components just described, the auxiliary piston head-0 may be undercut at 55 (FIG- URES 2 through adjacent zone 29 to permitthe passage of gases from chamber 29 into chamber 21. Conventional keyand groove means (not shown) may be provided between piston rod 51 andchamber 22 to insure registry between undercut 55 and zone 29, whilepermitting relative axial movement between rod 51 and chamber 22.

In use or operation of the improved internal com bustion engine, it willfirst be assumed that the component parts have been assembled as shownin FIGURE 1 of the drawings. It will further be assumed that thecomponent parts are in the specific positions shown in FIGURE 2 of thedrawings.

When the parts have been assembled as in FIGURE 2, they are in what maybe called the ignition position.

Accordingly, the primary piston and the auxiliary piston 50 are bothpositioned in the extreme upward position with further upward movementof the auxiliary piston 50 being prevented by the top wall 21a of thecylinder, while the main piston 40 is prevented from further upwardmovement by virtue of the fact that the crank has reached the top of itsstroke. It should also be noted that at this time, the protuberances 54,S4 abut the top surface 43 of the main piston 40, as shown in FIGURE 2,thereby spacing surface 52 from top surface 43. Thus, a firing zone 29is created in the chamber and between the top of the main piston 40 andthe bottom surface 52 of the auxiliary piston.

With the parts in this position, it will be assumed that a predeterminedamount of combustible gas has been compressed into the firing zone asshown by the arrow in FIGURE 2. The position of the other parts at thisstage should also be kept in mind, with the valve 32 being closed andthe by-pass and exhaust ports 23, 24 being open, thus allowing any gastrapped in conduit 26 from the preceding cycle to be evacuated.

Turning next to FIGURE 3, this figure shows the position of the partsimmediately following ignition Upon ignition of the gases trapped in thefiring zone 29 by the spark plug 28, the main piston 40 has been drivendownward in the combustion chamber 21 by the force of the explosion andthe eccentric arm 42 has rotated to position A which is approximately112 degrees from FIGURE 2. It will be noted at this time that the sameexpanding gases which drive the main piston 40 down will serve to retainthe auxiliary piston 50 in its original position against the top of thechamber 21. It should also be noted that some of the ignited gas hasentered in the bore of the main piston and that the by-pass and exhaustports 23, 24 have become closed.

Turning next to FIGURE 4, it will be noted that the main piston 40 hasnow been driven further downward so that the eccentric arm has nowrotated approximately 128 degrees from FIGURE 2 to position B. At thistime, it will be seen that the gases formerly trapped in the bore 45 arenow permitted to be expelled through the by-pass port 24 due to the factthat the bore 45 and the by-pass port 24 are now in registry. Thesegases pass through the conduit 26 and exert pressure on the top of theauxiliary piston rod 51. However, at this stage, this pressure is notsufficient to move the auxiliary piston from its original position byovercoming the pressure on its bottom surface.

In the position shown in FIGURE 5, it will be noted that the main piston40 has now moved downward so that the eccentric arm 4-2 has been rotatedapproximately 149 degrees from FIGURE 2 to position C. At this stage,both the by-pass and exhaust ports 23, 24 are still closed and the gastrapped in the conduit 26 is still exerting pressure on the top of theauxiliary piston rod 51. At this point, this pressure is still not greatenough to overcome appreciably the upward pressure of the exploding gasin the main combustion chamber 21.

In the phase depicted in FIGURE 6, the main piston has moved downward sothat the eccentric arm has now been rotated approximately 157 degreesfrom the position of FIGURE 2 to position D, with this downward movementbeing such that the exhaust port 23 is now partially open and the gastrapped in the main combustion chamber may now exit through the exhaustport, thereby diminishing the pressure in the chamber 22 which hasserved to retain the auxiliary piston essentially in its originalposition.

In FIGURE 7, the main piston has continued downward to its lowestposition so that the exhaust port is now completely open and theeccentric arm has rotated approximately degrees from FIGURE 2 toposition E. At this time, it will be noted that the gases previouslytrapped in the bypass conduit and exerting pressure on the top of theauxiliary piston rod 51 are now exerting sufiicient pressure to forcethe auxiliary piston 50 out of its original position.

At this time, it will also be noted that the main combustion chamber hasbeen divided into two subcham bers, with the first such subchamber beingformed by the bottom of the auxiliary piston head 50 and the top of themain piston 40. In this subchamber, the expanded gases are being drivenout through the exhaust port 23 by the downward movement of auxiliarypiston 50. At the same time, another subchamber has been created betweenthe top surface of the auxiliary piston head and the top 21a of the maincombustion chamber 21. Due to the downward movement of the auxiliarypiston head, a suction is created in this subchamber which causes theopening of the valve 32 by overcoming the force of the spring 33. Thispermits gas to be drawn in through the supply line 35 and thus throughthe valve 32 and into the subcompartment formed by the top of the maincombustion chamber and the auxiliary piston head.

In FIGURE 8, it will be seen that the main piston 40 and the auxiliarypiston 50 are in contact with each other. The eccentric arm has rotatedapproximately 199 degrees from FIGURE 2 to position F and the mainpiston and auxiliary piston have both started to move upward. At thistime, the exhaust port is still partially open, permitting the remainderof the gases trapped between the main and auxiliary pistons to beexpelled. The valve 32 will now start to close to terminate the entry offluid into the subcompartment formed by the auxiliary piston and the topof the main combustion chamber to be filled.

In FIGURE 9, it will be seen that the eccentric arm has rotatedapproximately 265 degrees from FIGURE 2 to position G and the main andauxiliary pistons have moved upward so as to close the exhaust port.This upward movement also has halted the vacuum effect caused by theauxiliary piston, thereby allowing the valve 32 to be closed by thespring 33. The same upward movement has the effect of compressing thegas trapped between the main and auxiliary pistons and the top of themain combustion chamber.

It should also be noted at this time that the remainder of the gases inthe auxiliary chamber 22 is forced back through the by-pass conduit 26by the upward movement of the auxiliary piston rod 51. This gas ismomentarily trapped therein due to the fact that the by-pass port 24 isstill closed.

In FIGURE 10, it will be noted that the eccentric arm has rotatedapproximately 338 degrees from FIG- URE 2 to position H and thecomponent parts have almost returned to the position of FIGURE 2. Atthis time, it can be seen that the by-pass port 24 is open, allowing thegas trapped in the conduit 26 to escape into the lower portion of themain combustion chamber toward the crank case.

It will also be noted that the gases trapped between the top of theauxiliary piston and the top of the main chamber are forced into theauxiliary zone 29 and thus into the chamber formed between the main andauxiliary pistons. This zone 29 is necessary to permit the gas to escapefrom between the auxiliary piston head and the top of the combustionchamber. As previously noted, the protuberances 54 preclude the main andauxiliary pistons from abutting and provide a chamber between them.

Upon further rotation of the eccentric arm, a full 360 degrees, theparts will be returned to the position shown in FIGURE 2. At this time,both the by-pass and exhaust ports 24, 23 are open and the remaining gastrapped in the by-pass conduit 26 can be expelled through the exhaustport. Also at this time, a predetermined amount of gas has beencompressed in the firing zone 29 and the engine is in condition for theinitiation of another power stroke, as just described, upon the ignitionof these gases by the spark plug 28.

In connection with the above, it is noted that the axial speed andmovement of main piston is controlled by crank 42, while auxiliarypiston is not controlled by any such means and is freely reciprocal.Accordingly, it is noted that auxiliary piston 50 will move at a muchhigher speed than main piston 40 during its downward movement.

With regard to the degrees of rotation described in connection withpositions A through H of FIGURES 2 through 10, it is noted that thesefigures have been given as approximate. Thus, they are utilized only forillustration purposes and the invention is not intended to be limited tothe specific degrees shown.

Thus, it can be seen that by virtue of the timed coaction between themain piston and the auxiliary piston it is possible to obtain a powerstroke in each cycle. This has been accomplished by having the auxiliarypiston perform the suction and exhaust functions normally accomplishedby separate strokes of the main piston and has further been accomplishedwithout any mechanical connection between the main and auxiliarypistons.

The net effect of the above is the production of an engine that in twocycles of operation produces the effect of a four cycle engine. Theattainment of this advantage does not require the admixture of the oiland gas together as is the case in normal two cycle engine operations,since the oil can be provided in the crank case as is obvious from theaforementioned description and does not need to be a constituent of thefuel being utilized as is normally the case in the operation of twocycle engines. It is also believed apparent that the subject matter ofthis invention is equally applicable to all types of internal combustionengines and particularly the invention would be applicable to beingutilized in connection with diesel engine operations wherein fuel isinjected and exploded by the heat of the fluid being compressed, with itbeing apparent that the charge could be injected through the member 32.

It is also to be understood that certain conventional details ofconstruction which do not pertain to the invention per se have beeneliminated for the sake of clarity. An example of the known constructionso eliminated is the detailed presentation of conventional sealing ringsthat would obviously be employed between the piston and circular wallsfor the purpose of providing a sealing effect in known manner.

While a full and complete description of the invention has been setforth in accordance with the dictates of the patent statutes, it is tobe understood that the invention is not intended to be limted to thespecific embodiment herein shown.

Accordingly, modifications of the invention may be resorted to withoutdeparting from the spirit hereof or the scope of the appended claims.

What is claimed is:

1. A combustion engine of the character described, comprising:

(A) a combustion chamber having inlet and exhaust ports and furtherincluding an auxiliary chamber;

(B) aprimary piston (l) reciproeable in said combustion chamber betweenupper and lower positions and (2) havinga top surface;

(C) a secondary piston (1) slidably positioned above said primary pistonin said combustion chamber and (2) having imperforate upper and lowersurfaces and (3) being shiftable between upper and lower positions',

(D) ignition means (1) adapted to ignite gases trapped between saidprimary and secondary pistons when the same are in said upper positions(a) whereby said primary piston will be driven downwardly in a powerstroke;

(E) by-pass means carried by said primary piston and said combustionchamber (1) diverting a portion of said ignited gases out of saidcombustion chamber and against the upper surface of said secondarypiston following a predetermined amount of downward movement of saidprimary piston in said power stroke (a) whereby said diverted gasespropel said secondary piston downwardly during said downward stroke;

(F) and means disposed on one of said pistons maintaining a spacedrelationship between said lower surface of said secondary piston andsaid upper surface of said primary piston.

2. The device of claim 1 further characterized by the fact that saidby-pass means include (A) an angular opening connecting the top surfaceof said primary piston with the peripheral edge thereof;

(B) and aconduit (1) having one end opening into said auxiliary chamberat a point above the top surface of said secondary piston when the sameis positioned in its upper position and (2) having the other end thereofopening into said combustion chamber for registry with said peripheralopening during said power stroke.

3. The device of claim 1 further characterized by the face that saidexhaust port opens into said combustion chamber above said top surfaceof said primary piston when said piston is in its lower position wherebysaid secondary piston sweeps said ignited gases out of said exhaust portduring said downward movement thereof that occurs during said powerstroke of said primary piston.

4. The device of claim 1 further characterized by fact that the presenceof a spring loaded valve in said inlet port with said valve beingmovable between seated and onseated positions and being normally seatedto close off said inlet port while being movable to unseated position inresponse to suction forces created by downward movement of saidsecondary piston whereby said secondary piston automatically draws in anew charge of fuel from said inlet port during said downward movementthereof that occurs during said power stroke of said primary piston.

5. The device of claim 1 further characterized by the presence of reliefmeans adapted to relieve the propelling force of said diverted gasfollowing completion of said power stroke by said primary piston.

6. The device of claim 1 further characterized by the fact that (A) saidcombustion chamber has an offset portion disposed adjacent its upperend; and

(B) said secondary piston has an undercut portion on its lower surfacefor registry with said offset portion of said combustion chamber,whereby compressed fuel may be diverted into the space between saidprimary and secondary pistons during upward movement thereof.

7. The device of claim 1 wherein (A) said exhaust port opens into saidcombustion chamber above said top surface of said primary piston whensaid piston is in its lower position; and

(B) a spring loaded valve is disposed in said inlet port with said valvebeing movable between seated and unseated positions and being normallyseated to close oif said inlet port while being movable to unseatedposition in response to suction forces created by downward movement ofsaid secondary piston (1) whereby said secondary piston sweeps saidignited gases out of said exhaust port during said downward movementthereof that occurs during said power stroke of said primary pistonWhile simultaneously automatically drawing in a new charge of fuelthrough said inlet port.

8. The device of claim 1 wherein (A) said secondary piston contacts saidprimary piston when said secondary and said primary pistons are at theirlower positions; and

(B) said inlet port being disposed above said secondary piston when saidsecondary piston is at its lower position; and

(C) said primary and secondary pistons move upwardly in unison (1)whereby said primary and secondary pistons compress the gas in saidchamber during their upward movement.

9. A combustion engine of the character described,

comprising;

(A) a combustion chamber having inlet and exhaust ports and furtherincluding an auxiliary chamber,-

(B) a primary piston (l) reciprocable in said combustion chamber betweenupper and lower positions and (2) having a top surface;

(C) a secondary piston (1) slidably positioned above said primary pistonin said combustion chamber and (2) having imperforate upper and lowersurfaces and (3) being shiftable between upper and lower positions;

(D) ignition means (1) adapted to ignite gases trapped between saidprimary and secondary pistons when the same are in said upper positions(a) whereby said primary piston will be driven downw dly in a powerstroke,- (E) by-pass means including (1) a conduit (a) disposedexternally of said combustion chamber and (b) interconnecting saidcombustion chamber, at a point below the bottom surface of saidsecondary piston when the same is in its upper position, with saidauxiliary chamber at a point ab ve said top surface of said secondarypiston (1 whereby a portion of said ignited gases may be diverted out ofsaid cornbustion chamber, into said conduit, and thence into saidauxiliary chamber for contact with said upper surface of said sec ndarypiston following a predetermined amount of downward movement of saidprimary piston in its power stroke to propel said secondary pistondownwardly;

(F) and means disposed on One of said pistons for maintaining a spacedrelationship between said lower surface of said secondary piston andsaid upper surface of said primary piston.

10. The device of claim 9 further characterized by the presence ofsecond by-pass means diverting entrapped gas from said inlet port from aposition above said scconrb nry piston to a position between saidprimary and secondary pistrms during the period said pistons are movingupwardly toward their upper positions.

References Cited by the Examiner The following references, cited by theExaminer, are of record in the patented file of this patent or theoriginal patent.

UNITED STATES PATENTS 895,184 8/1908 Kelly 123-66 1,586,342 1/1926MacFarlane l23-66 FOREIGN PATENTS 384,598 2/1908 France.

MARK NEWMAN, Primary Examiner. W. E. BURNS, Assistant Examiner.

